<!DOCTYPE html>



  


<html class="theme-next pisces use-motion" lang="zh-Hans">
<head>
  <meta charset="UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"/>
<meta name="theme-color" content="#222">









<meta http-equiv="Cache-Control" content="no-transform" />
<meta http-equiv="Cache-Control" content="no-siteapp" />
















  
  
  <link href="/blog/lib/fancybox/source/jquery.fancybox.css?v=2.1.5" rel="stylesheet" type="text/css" />







<link href="/blog/lib/font-awesome/css/font-awesome.min.css?v=4.6.2" rel="stylesheet" type="text/css" />

<link href="/blog/css/main.css?v=5.1.4" rel="stylesheet" type="text/css" />


  <link rel="apple-touch-icon" sizes="180x180" href="/blog/images/apple-touch-icon-next.png?v=5.1.4">


  <link rel="icon" type="image/png" sizes="32x32" href="/blog/images/favicon-32x32-next.png?v=5.1.4">


  <link rel="icon" type="image/png" sizes="16x16" href="/blog/images/favicon-16x16-next.png?v=5.1.4">


  <link rel="mask-icon" href="/blog/images/logo.svg?v=5.1.4" color="#222">





  <meta name="keywords" content="c++," />





  <link rel="alternate" href="/blog/atom.xml" title="伏窗尾的猫" type="application/atom+xml" />






<meta name="description" content="c++类综述一个带类的c++伪函数如下： &amp;gt;#include&amp;lt;iostream&amp;gt;//头文件 using namespace std;//命名空间   struct List//定义一个结构体(默认公有：public) {     int data;     List *next; }  class Date//定义了一个类(默认私有：private) { public://公有成">
<meta name="keywords" content="c++">
<meta property="og:type" content="article">
<meta property="og:title" content="c++学习概述">
<meta property="og:url" content="http://eidolon_x.gitee.io/blog/2018/10/11/c-学习概述/index.html">
<meta property="og:site_name" content="伏窗尾的猫">
<meta property="og:description" content="c++类综述一个带类的c++伪函数如下： &amp;gt;#include&amp;lt;iostream&amp;gt;//头文件 using namespace std;//命名空间   struct List//定义一个结构体(默认公有：public) {     int data;     List *next; }  class Date//定义了一个类(默认私有：private) { public://公有成">
<meta property="og:locale" content="zh-Hans">
<meta property="og:updated_time" content="2021-01-18T07:27:02.928Z">
<meta name="twitter:card" content="summary">
<meta name="twitter:title" content="c++学习概述">
<meta name="twitter:description" content="c++类综述一个带类的c++伪函数如下： &amp;gt;#include&amp;lt;iostream&amp;gt;//头文件 using namespace std;//命名空间   struct List//定义一个结构体(默认公有：public) {     int data;     List *next; }  class Date//定义了一个类(默认私有：private) { public://公有成">



<script type="text/javascript" id="hexo.configurations">
  var NexT = window.NexT || {};
  var CONFIG = {
    root: '/blog/',
    scheme: 'Pisces',
    version: '5.1.4',
    sidebar: {"position":"left","display":"post","offset":12,"b2t":true,"scrollpercent":false,"onmobile":false},
    fancybox: true,
    tabs: true,
    motion: {"enable":true,"async":false,"transition":{"post_block":"fadeIn","post_header":"slideDownIn","post_body":"slideDownIn","coll_header":"slideLeftIn","sidebar":"slideUpIn"}},
    duoshuo: {
      userId: '0',
      author: '博主'
    },
    algolia: {
      applicationID: '',
      apiKey: '',
      indexName: '',
      hits: {"per_page":10},
      labels: {"input_placeholder":"Search for Posts","hits_empty":"We didn't find any results for the search: ${query}","hits_stats":"${hits} results found in ${time} ms"}
    }
  };
</script>



  <link rel="canonical" href="http://eidolon_x.gitee.io/blog/2018/10/11/c-学习概述/"/>





  <title>c++学习概述 | 伏窗尾的猫</title>
  








</head>

<body itemscope itemtype="http://schema.org/WebPage" lang="zh-Hans">

  
  
    
  

  <div class="container sidebar-position-left page-post-detail">
    <div class="headband"></div>

    <header id="header" class="header" itemscope itemtype="http://schema.org/WPHeader">
      <div class="header-inner"><div class="site-brand-wrapper">
  <div class="site-meta ">
    

    <div class="custom-logo-site-title">
      <a href="/blog/"  class="brand" rel="start">
        <span class="logo-line-before"><i></i></span>
        <span class="site-title">伏窗尾的猫</span>
        <span class="logo-line-after"><i></i></span>
      </a>
    </div>
      
        <p class="site-subtitle"></p>
      
  </div>

  <div class="site-nav-toggle">
    <button>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
    </button>
  </div>
</div>

<nav class="site-nav">
  

  
    <ul id="menu" class="menu">
      
        
        <li class="menu-item menu-item-home">
          <a href="/blog/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-home"></i> <br />
            
            首页
          </a>
        </li>
      
        
        <li class="menu-item menu-item-tags">
          <a href="/blog/tags/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-tags"></i> <br />
            
            标签
          </a>
        </li>
      
        
        <li class="menu-item menu-item-categories">
          <a href="/blog/categories/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-th"></i> <br />
            
            分类
          </a>
        </li>
      
        
        <li class="menu-item menu-item-archives">
          <a href="/blog/archives/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-archive"></i> <br />
            
            归档
          </a>
        </li>
      

      
        <li class="menu-item menu-item-search">
          
            <a href="javascript:;" class="popup-trigger">
          
            
              <i class="menu-item-icon fa fa-search fa-fw"></i> <br />
            
            搜索
          </a>
        </li>
      
    </ul>
  

  
    <div class="site-search">
      
  <div class="popup search-popup local-search-popup">
  <div class="local-search-header clearfix">
    <span class="search-icon">
      <i class="fa fa-search"></i>
    </span>
    <span class="popup-btn-close">
      <i class="fa fa-times-circle"></i>
    </span>
    <div class="local-search-input-wrapper">
      <input autocomplete="off"
             placeholder="搜索..." spellcheck="false"
             type="text" id="local-search-input">
    </div>
  </div>
  <div id="local-search-result"></div>
</div>



    </div>
  
</nav>



 </div>
    </header>

    <main id="main" class="main">
      <div class="main-inner">
        <div class="content-wrap">
          <div id="content" class="content">
            

  <div id="posts" class="posts-expand">
    

  

  
  
  

  <article class="post post-type-normal" itemscope itemtype="http://schema.org/Article">
  
  
  
  <div class="post-block">
    <link itemprop="mainEntityOfPage" href="http://eidolon_x.gitee.io/blog/blog/2018/10/11/c-学习概述/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="name" content="喵呜">
      <meta itemprop="description" content="">
      <meta itemprop="image" content="/blog/images/1.jpg">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="伏窗尾的猫">
    </span>

    
      <header class="post-header">

        
        
          <h1 class="post-title" itemprop="name headline">c++学习概述</h1>
        

        <div class="post-meta">
		
          <span class="post-time">
            
              <span class="post-meta-item-icon">
                <i class="fa fa-calendar-o"></i>
              </span>
              
                <span class="post-meta-item-text">发表于</span>
              
              <time title="创建于" itemprop="dateCreated datePublished" datetime="2018-10-11T10:46:48+08:00">
                2018-10-11
              </time>
            

            
              <span class="post-meta-divider">|</span>
            

            
              <span class="post-meta-item-icon">
                <i class="fa fa-calendar-check-o"></i>
              </span>
              
                <span class="post-meta-item-text">更新于&#58;</span>
              
              <time title="更新于" itemprop="dateModified" datetime="2021-01-18T15:27:02+08:00">
                2021-01-18
              </time>
            
          </span>

          
            <span class="post-category" >
            
              <span class="post-meta-divider">|</span>
            
              <span class="post-meta-item-icon">
                <i class="fa fa-folder-o"></i>
              </span>
              
                <span class="post-meta-item-text">分类于</span>
              
              
                <span itemprop="about" itemscope itemtype="http://schema.org/Thing">
                  <a href="/blog/categories/学习之路/" itemprop="url" rel="index">
                    <span itemprop="name">学习之路</span>
                  </a>
                </span>

                
                
              
            </span>
          

          
            
          

          
          
             <span id="/blog/2018/10/11/c-学习概述/" class="leancloud_visitors" data-flag-title="c++学习概述">
               <span class="post-meta-divider">|</span>
               <span class="post-meta-item-icon">
                 <i class="fa fa-eye"></i>
               </span>
               
                 <span class="post-meta-item-text">热度&#58;</span>
               
                 <span class="leancloud-visitors-count"></span>
				 <span>℃<span>
             </span>
          

          

		  
			  <span class="post-meta-divider">|</span>
			  <span id="busuanzi_value_page_pv"></span>次阅读
		  
          

          

        </div>
      </header>
    

    
    
    
    <div class="post-body" itemprop="articleBody">

      
      

      
        <h1 id="c-类综述"><a href="#c-类综述" class="headerlink" title="c++类综述"></a>c++类综述</h1><p>一个带类的c++伪函数如下：</p>
<pre><code>&gt;#include&lt;iostream&gt;//头文件
using namespace std;//命名空间


struct List//定义一个结构体(默认公有：public)
{
    int data;
    List *next;
}

class Date//定义了一个类(默认私有：private)
{
public://公有成员，均可访问

    Date(){}//默认构造函数

    Date(int y,int m,int d)//带参数的构造函数，使用函数重载
                          //函数重载：同作用域，相同的函数名，不同的参数(返回值可不同)
    {
        this-&gt;y = y;//this指针，一个隐含形参，不知实例对象时用this替代。也可以说this指向对象本身
        this-&gt;m = m;//在这里的用法是这个类中的为这个类中的成员变量赋值形参m的值
        this-&gt;d = d;
    }

    Date(int y = 0,int m = 0,int d = 0){}//普通带参的构造函数

    Point(const Date&amp; p)//拷贝构造函数,用一个已经存在的对象构建一个新的对象
    {                    //不显式声明，会自动生成拷贝构造函数，且为浅拷贝(逐成员赋值)
                        //以下为浅拷贝，相当于值传递
                        //拷贝函数是对本类类型的常引用
        cout &lt;&lt; &quot;拷贝构造函数&quot; &lt;&lt; endl;
        this-&gt;y = p.x;
        this-&gt;m = p.y;
        this-&gt;d = p.d;
    }




    void show()//类内定义成员函数
    {
        cout &lt;&lt; &quot;Date(&quot;&lt;&lt; y &lt;&lt; &quot;/&quot; &lt;&lt; m &lt;&lt; &quot;/&quot; &lt;&lt; d &lt;&lt; &quot;)&quot; &lt;&lt; endl;
    }
    void get_year();//类内声明，类外定义成员函数



    friend void foo(Date date);//友元函数声明
    friend class Student;//声明一个友元类，友元类中的函数均是本类的友元函数

private://私有成员，通常只能类内访问
    int y;
    int m;
    int d;


    //static 静态成员不是对象成员
    static int count;//静态成员变量，存在于静态存储区，仅本文件可见，被所有同类的对象共享

    static void get_day();//静态成员函数，不与任何对象相联系，没有this指针，仅能调用静态成员变量和静态成员函数
};

int Student::count = 0;//静态成员变量的类外初始化，不初始化就是0


void foo(Date date)    //一个在Date中声明的友元函数，可直接访问类的私有成员。
{                            //是一个定义在类外的普通函数，不属于类
    cout &lt;&lt; date.y &lt;&lt; endl;
}

void Date::get_year()//类外定义成员函数，要带上作用域
{
    cout &lt;&lt; this.y &lt;&lt; endl;
}

void swap3(int &amp;a,int &amp;b)//一个普通函数，使用了引用作为参数
{                        //调用时直接把变量当作实参即可，这里的形参就成了实参的比个别名
    int t;                //引用还可以用作返回值
    t = a;
    a = b;
    b = t;
}
float &amp;fn2(float r)//它以引用方式返回函数值，好处是不用给返回值开辟一段新的空间
{
　temp=(float)(r*r*3.14);
　return temp;
}

class Student
{
public:
    Student():birthday(1,1,1)//
    {
        id = 0;
        name = &quot;&quot;;
    }
    Student(int id,string name,Date birth):id(id),name(name),birthday(birth){}
    //初始值列表，用于在对象构造前对值得初始化
    //按照声明的顺序初始化
    //有常量，有引用，和没有默认构造函数的类类型的成员变量必用

    Student(const Student&amp; s)//拷贝构造函数(深拷贝)
    {                        //当成员变量是指针时，不能简单的浅拷贝，要给指针指向的对象
                            //new一块空间出来保存。而后在析构函数中delate掉。
                            //不如此，则会double free。
        //this-&gt;name = s.name; //浅拷贝
        cout &lt;&lt; &quot;my copy constructor...&quot; &lt;&lt; endl;
        int len = strlen(s.name) + 1;
        this-&gt;name = new char[len];
        memcpy(this-&gt;name,s.name,len);
    }
    Student&amp; operator=(const Student &amp;s)    //赋值运算符重载
    {                                            
        cout &lt;&lt; &quot;赋值运算符重载函数&quot; &lt;&lt; endl;//运算符重载:返回类型 operator运算符(参数)
        //this-&gt;name = s.name;

        if(this != &amp;s)
        {
            delete []name;
            this-&gt;name = new char[strlen(s.name)+1];
            strcpy(this-&gt;name,s.name);
        }
        return *this;

    }

    ~Student()
    {
        delete []name;
    }//析构函数
    void show()
    {
        cout &lt;&lt; id &lt;&lt; name &lt;&lt; endl;
        birthday.show();//类的组合，代码重用
    }

private:
    int id;
    string name;
    Date birthday;
};

int main()
{
    Student s;//调用Student无参数的构造函数
    Date date(1999,9,9);//调用Date有参数的构造函数
    Student s1(1001,&quot;zhangfei&quot;,date);//调用有参数的student的构造函数
    s1.show();//函数重用

    Student s2(s1);//调用拷贝构造函数
    s2.show();

    Student s3;
    s3 = s2;//运算符重载
    s3.show();
    return 0;
}
</code></pre><p>以上，介绍了几种c++类的相关概念及用法：</p>
<h2 id="类成员函数："><a href="#类成员函数：" class="headerlink" title="类成员函数："></a>类成员函数：</h2><p>类的成员函数是指那些把定义和原型写在类定义内部的函数，就像类定义中的其他变量一样。能类内定义和类外定义，类外要加上作用域，用法</p>
<blockquote>
<p>类型 类：： 函数名。//类型加上作用域加上函数名</p>
</blockquote>
<h2 id="访问修饰符："><a href="#访问修饰符：" class="headerlink" title="访问修饰符："></a>访问修饰符：</h2><blockquote>
<p>public：公有//struct默认公有</p>
<p>private:私有//class默认私有</p>
<p>protected:保护成员</p>
<p>operator：运算符重载</p>
</blockquote>
<p>运算符重载用法</p>
<blockquote>
<p>类型 operator运算符（参数）</p>
</blockquote>
<h2 id="构造函数-amp-析构函数"><a href="#构造函数-amp-析构函数" class="headerlink" title="构造函数&amp;析构函数"></a>构造函数&amp;析构函数</h2><p>类的构造函数是一种特殊的函数，在创建一个新的对象时调用。类的析构函数也是一种特殊的函数，在删除所创建的对象时调用。</p>
<h3 id="构造函数："><a href="#构造函数：" class="headerlink" title="构造函数："></a>构造函数：</h3><p>有不带参数的构造函数和带参数的构造函数，通过函数重载实现根据不同的参数来实现调用不同的构造函数。</p>
<p>带参数的构造函数中还有一种带初值的构造函数，如果有参数则按参数赋值，没有则赋初值，属于默认构造函数，默认构造函数就是不带参数就可以调用的构造函数。</p>
<p>还有运用初始化列表的构造函数，因为在调用构造函数时有两个阶段，初始化阶段和计算阶段。所有类类型的成员都会在初始化阶段初始化，即使该成员没有出现在构造函数的初始化列表中。</p>
<ul>
<li>常量成员，因为常量只能初始化不能赋值，所以必须放在初始化列表里面</li>
<li>引用类型，引用必须在定义的时候初始化，并且不能重新赋值，所以也要写在初始化列表里面</li>
<li>没有默认构造函数的类类型，因为使用初始化列表可以不必调用默认构造函数来初始化，而是直接调用拷贝构造函数初始化。</li>
</ul>
<h3 id="拷贝构造函数"><a href="#拷贝构造函数" class="headerlink" title="拷贝构造函数"></a>拷贝构造函数</h3><p>　　将一个对象的内容拷贝给相同的类，<strong>用一个已经存在的对象去初始化另一个对象</strong>，两个对象的类型应该相同。拷贝构造函数参数是本类类型的常引用，如果没有显式声明拷贝构造函数，则会隐式生成，并是浅拷贝，逐成员赋值。 </p>
<p>　　如果类中有指针类型的成员变量，则需要进行深拷贝，需要new一块与原对象指针所指向的地址空间同等大小的地址空间，并将其内容复制至新的地址，否则在调用析构函数时，将对同一块空间double free,报错。</p>
<h3 id="友元"><a href="#友元" class="headerlink" title="友元"></a>友元</h3><p>类的友元函数是定义在类外部，但有权访问类的所有私有（private）成员和保护（protected）成员。友元函数的原型在类的定义时在原型前加上关键字friend，但是友元函数并不是成员函数。友元类同理，友元类中所有的函数都是原类的友元函数。<br>因为友元函数没有this指针，则参数要有三种情况： </p>
<ul>
<li><p>要访问非static成员时，需要对象做参数；</p>
</li>
<li><p>要访问static成员或全局变量时，则不需要对象做参数；</p>
</li>
<li><p>如果做参数的对象是全局对象，则不需要对象做参数.可以直接调用友元函数，不需要通过对象或指针；</p>
</li>
</ul>
<h3 id="this指针"><a href="#this指针" class="headerlink" title="this指针"></a>this指针</h3><p>类中有一个很关键的指针，每一个对象都能通过 this 指针来访问自己的地址。this 指针是所有成员函数的隐含参数。因此，在成员函数内部，它可以用来指向调用对象。this是一个常量指针，指向“这个对象”。改变this指针是错误的行为。常用于使用this区分形参和对象成员变量，也常见于返回值，返回“这个对象”。</p>
<h3 id="静态成员"><a href="#静态成员" class="headerlink" title="静态成员"></a>静态成员</h3><p>类中有一个静态成员的概念，关键字static，不管有多少个对象，静态成员只有一个。静态成员在类的所有对象中是共享的。如果不初始化，在创建第一个对象时，所有的静态数据都会被初始化为零。我们不能把静态成员的初始化放置在类的定义中，但是可以在类的外部通过使用范围解析运算符 :: 来重新声明静态变量从而对它进行初始化。</p>
<p><strong>静态成员变量存储于静态全局区</strong>。</p>
<p>如果把函数成员声明为静态的，就可以把函数与类的任何特定对象独立开来。静态成员函数即使在类对象不存在的情况下也能被调用，静态函数只要使用类名加范围解析运算符 :: 就可以访问。</p>
<p>静态成员函数只能访问静态成员数据、其他静态成员函数和类外部的其他函数。</p>
<p>静态成员函数有一个类范围，他们不能访问类的 this 指针。</p>

      
    </div>
    
    
    
	
	<div>
	  
		<div>
    
        <div style="text-align:center;color: #ccc;font-size:14px;">------ 本文结束------</div>
    
</div>
	  
	</div>
	

    

    

    
      <div>
        <ul class="post-copyright">
  <li class="post-copyright-author">
    <strong>本文作者：</strong>
    喵呜  |  喵呜
  </li>
  <li class="post-copyright-link">
    <strong>本文链接：</strong>
    <a href="http://eidolon_x.gitee.io/blog/2018/10/11/c-学习概述/" title="c++学习概述">http://eidolon_x.gitee.io/blog/2018/10/11/c-学习概述/</a>
  </li>
  <li class="post-copyright-license">
    <strong>版权声明： </strong>
    本博客所有文章除特别声明外，均采用 <a href="https://creativecommons.org/licenses/by-nc-sa/3.0/" rel="external nofollow" target="_blank">CC BY-NC-SA 3.0</a> 许可协议。转载请注明出处！
  </li>
  <li class="post-copyright-license">
    并保留本声明和上方二维码。感谢您的阅读和支持！
  </li>
</ul>
      </div>
    

    <footer class="post-footer">
      
        <div class="post-tags">
          
            <a href="/blog/tags/c/" rel="tag"># c++</a>
          
        </div>
      

      
      
      

      
        <div class="post-nav">
          <div class="post-nav-next post-nav-item">
            
              <a href="/blog/2018/09/28/学习之路——进程间通信/" rel="next" title="学习之路——进程与线程（三）">
                <i class="fa fa-chevron-left"></i> 学习之路——进程与线程（三）
              </a>
            
          </div>

          <span class="post-nav-divider"></span>

          <div class="post-nav-prev post-nav-item">
            
              <a href="/blog/2018/10/15/linux安装arm-linux-gcc交叉编译环境/" rel="prev" title="linux安装arm-linux-gcc交叉编译环境">
                linux安装arm-linux-gcc交叉编译环境 <i class="fa fa-chevron-right"></i>
              </a>
            
          </div>
        </div>
      

      
      
    </footer>
  </div>
  
  
  
  </article>



    <div class="post-spread">
      
    </div>
  </div>


          </div>
          


          

  



        </div>
        
          
  
  <div class="sidebar-toggle">
    <div class="sidebar-toggle-line-wrap">
      <span class="sidebar-toggle-line sidebar-toggle-line-first"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-middle"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-last"></span>
    </div>
  </div>

  <aside id="sidebar" class="sidebar">
    
    <div class="sidebar-inner">

      

      
        <ul class="sidebar-nav motion-element">
          <li class="sidebar-nav-toc sidebar-nav-active" data-target="post-toc-wrap">
            文章目录
          </li>
          <li class="sidebar-nav-overview" data-target="site-overview-wrap">
            站点概览
          </li>
        </ul>
      

      <section class="site-overview-wrap sidebar-panel">
        <div class="site-overview">
          <div class="site-author motion-element" itemprop="author" itemscope itemtype="http://schema.org/Person">
            
              <img class="site-author-image" itemprop="image"
                src="/blog/images/1.jpg"
                alt="喵呜" />
            
              <p class="site-author-name" itemprop="name">喵呜</p>
              <p class="site-description motion-element" itemprop="description"></p>
          </div>

          <nav class="site-state motion-element">

            
              <div class="site-state-item site-state-posts">
              
                <a href="/blog/archives/">
              
                  <span class="site-state-item-count">20</span>
                  <span class="site-state-item-name">日志</span>
                </a>
              </div>
            

            
              
              
              <div class="site-state-item site-state-categories">
                <a href="/blog/categories/index-1.html">
                  <span class="site-state-item-count">5</span>
                  <span class="site-state-item-name">分类</span>
                </a>
              </div>
            

			
			  <div class="site-state-item site-state-tags">
				<a href="/blog/tags/ || tags">
				  <span class="site-state-item-count">13</span>
				  <span class="site-state-item-name">标签</span>
				</a>
			  </div>
			

          </nav>

          
            <div class="feed-link motion-element">
              <a href="/blog/atom.xml" rel="alternate">
                <i class="fa fa-rss"></i>
                RSS
              </a>
            </div>
          

          

          
          

          
          

          

        </div>
      </section>

      
      <!--noindex-->
        <section class="post-toc-wrap motion-element sidebar-panel sidebar-panel-active">
          <div class="post-toc">

            
              
            

            
              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-1"><a class="nav-link" href="#c-类综述"><span class="nav-text">c++类综述</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#类成员函数："><span class="nav-text">类成员函数：</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#访问修饰符："><span class="nav-text">访问修饰符：</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#构造函数-amp-析构函数"><span class="nav-text">构造函数&amp;析构函数</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#构造函数："><span class="nav-text">构造函数：</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#拷贝构造函数"><span class="nav-text">拷贝构造函数</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#友元"><span class="nav-text">友元</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#this指针"><span class="nav-text">this指针</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#静态成员"><span class="nav-text">静态成员</span></a></li></ol></li></ol></li></ol></div>
            

          </div>
        </section>
      <!--/noindex-->
      

      
        <div class="back-to-top">
          <i class="fa fa-arrow-up"></i>
          
        </div>
      

    </div>
  </aside>


        
      </div>
    </main>

    <footer id="footer" class="footer">
      <div class="footer-inner">
        <div class="copyright">&copy; <span itemprop="copyrightYear">2021</span>
  <span class="with-love">
    <i class="fa fa-user"></i>
  </span>
  <span class="author" itemprop="copyrightHolder">喵呜</span>

  
</div>

<div>
<script async src="https://dn-lbstatics.qbox.me/busuanzi/2.3/busuanzi.pure.mini.js"></script>
<span id="busuanzi_container_site_pv" style='display:none'>
    本站总访问量 <span id="busuanzi_value_site_pv"></span> 次
    <span class="post-meta-divider">|</span>
</span>
<span id="busuanzi_container_site_uv" style='display:none'>
    有<span id="busuanzi_value_site_uv"></span>人看过我的博客啦
</span>
</div>


  <div class="powered-by">QQ  母胎solo </div>



  <span class="post-meta-divider">|</span>



  <div class="theme-info">微信：请勿撩骚 &mdash;  v5.1.4</div>




        







        
      </div>
    </footer>

    

    

  </div>

  

<script type="text/javascript">
  if (Object.prototype.toString.call(window.Promise) !== '[object Function]') {
    window.Promise = null;
  }
</script>









  


  











  
  
    <script type="text/javascript" src="/blog/lib/jquery/index.js?v=2.1.3"></script>
  

  
  
    <script type="text/javascript" src="/blog/lib/fastclick/lib/fastclick.min.js?v=1.0.6"></script>
  

  
  
    <script type="text/javascript" src="/blog/lib/jquery_lazyload/jquery.lazyload.js?v=1.9.7"></script>
  

  
  
    <script type="text/javascript" src="/blog/lib/velocity/velocity.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/blog/lib/velocity/velocity.ui.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/blog/lib/fancybox/source/jquery.fancybox.pack.js?v=2.1.5"></script>
  

  
  
    <script type="text/javascript" src="/blog/lib/canvas-nest/canvas-nest.min.js"></script>
  


  


  <script type="text/javascript" src="/blog/js/src/utils.js?v=5.1.4"></script>

  <script type="text/javascript" src="/blog/js/src/motion.js?v=5.1.4"></script>



  
  


  <script type="text/javascript" src="/blog/js/src/affix.js?v=5.1.4"></script>

  <script type="text/javascript" src="/blog/js/src/schemes/pisces.js?v=5.1.4"></script>



  
  <script type="text/javascript" src="/blog/js/src/scrollspy.js?v=5.1.4"></script>
<script type="text/javascript" src="/blog/js/src/post-details.js?v=5.1.4"></script>



  


  <script type="text/javascript" src="/blog/js/src/bootstrap.js?v=5.1.4"></script>



  


  




	





  





  












  

  <script type="text/javascript">
    // Popup Window;
    var isfetched = false;
    var isXml = true;
    // Search DB path;
    var search_path = "search.xml";
    if (search_path.length === 0) {
      search_path = "search.xml";
    } else if (/json$/i.test(search_path)) {
      isXml = false;
    }
    var path = "/blog/" + search_path;
    // monitor main search box;

    var onPopupClose = function (e) {
      $('.popup').hide();
      $('#local-search-input').val('');
      $('.search-result-list').remove();
      $('#no-result').remove();
      $(".local-search-pop-overlay").remove();
      $('body').css('overflow', '');
    }

    function proceedsearch() {
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay"></div>')
        .css('overflow', 'hidden');
      $('.search-popup-overlay').click(onPopupClose);
      $('.popup').toggle();
      var $localSearchInput = $('#local-search-input');
      $localSearchInput.attr("autocapitalize", "none");
      $localSearchInput.attr("autocorrect", "off");
      $localSearchInput.focus();
    }

    // search function;
    var searchFunc = function(path, search_id, content_id) {
      'use strict';

      // start loading animation
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay">' +
          '<div id="search-loading-icon">' +
          '<i class="fa fa-spinner fa-pulse fa-5x fa-fw"></i>' +
          '</div>' +
          '</div>')
        .css('overflow', 'hidden');
      $("#search-loading-icon").css('margin', '20% auto 0 auto').css('text-align', 'center');

      $.ajax({
        url: path,
        dataType: isXml ? "xml" : "json",
        async: true,
        success: function(res) {
          // get the contents from search data
          isfetched = true;
          $('.popup').detach().appendTo('.header-inner');
          var datas = isXml ? $("entry", res).map(function() {
            return {
              title: $("title", this).text(),
              content: $("content",this).text(),
              url: $("url" , this).text()
            };
          }).get() : res;
          var input = document.getElementById(search_id);
          var resultContent = document.getElementById(content_id);
          var inputEventFunction = function() {
            var searchText = input.value.trim().toLowerCase();
            var keywords = searchText.split(/[\s\-]+/);
            if (keywords.length > 1) {
              keywords.push(searchText);
            }
            var resultItems = [];
            if (searchText.length > 0) {
              // perform local searching
              datas.forEach(function(data) {
                var isMatch = false;
                var hitCount = 0;
                var searchTextCount = 0;
                var title = data.title.trim();
                var titleInLowerCase = title.toLowerCase();
                var content = data.content.trim().replace(/<[^>]+>/g,"");
                var contentInLowerCase = content.toLowerCase();
                var articleUrl = decodeURIComponent(data.url);
                var indexOfTitle = [];
                var indexOfContent = [];
                // only match articles with not empty titles
                if(title != '') {
                  keywords.forEach(function(keyword) {
                    function getIndexByWord(word, text, caseSensitive) {
                      var wordLen = word.length;
                      if (wordLen === 0) {
                        return [];
                      }
                      var startPosition = 0, position = [], index = [];
                      if (!caseSensitive) {
                        text = text.toLowerCase();
                        word = word.toLowerCase();
                      }
                      while ((position = text.indexOf(word, startPosition)) > -1) {
                        index.push({position: position, word: word});
                        startPosition = position + wordLen;
                      }
                      return index;
                    }

                    indexOfTitle = indexOfTitle.concat(getIndexByWord(keyword, titleInLowerCase, false));
                    indexOfContent = indexOfContent.concat(getIndexByWord(keyword, contentInLowerCase, false));
                  });
                  if (indexOfTitle.length > 0 || indexOfContent.length > 0) {
                    isMatch = true;
                    hitCount = indexOfTitle.length + indexOfContent.length;
                  }
                }

                // show search results

                if (isMatch) {
                  // sort index by position of keyword

                  [indexOfTitle, indexOfContent].forEach(function (index) {
                    index.sort(function (itemLeft, itemRight) {
                      if (itemRight.position !== itemLeft.position) {
                        return itemRight.position - itemLeft.position;
                      } else {
                        return itemLeft.word.length - itemRight.word.length;
                      }
                    });
                  });

                  // merge hits into slices

                  function mergeIntoSlice(text, start, end, index) {
                    var item = index[index.length - 1];
                    var position = item.position;
                    var word = item.word;
                    var hits = [];
                    var searchTextCountInSlice = 0;
                    while (position + word.length <= end && index.length != 0) {
                      if (word === searchText) {
                        searchTextCountInSlice++;
                      }
                      hits.push({position: position, length: word.length});
                      var wordEnd = position + word.length;

                      // move to next position of hit

                      index.pop();
                      while (index.length != 0) {
                        item = index[index.length - 1];
                        position = item.position;
                        word = item.word;
                        if (wordEnd > position) {
                          index.pop();
                        } else {
                          break;
                        }
                      }
                    }
                    searchTextCount += searchTextCountInSlice;
                    return {
                      hits: hits,
                      start: start,
                      end: end,
                      searchTextCount: searchTextCountInSlice
                    };
                  }

                  var slicesOfTitle = [];
                  if (indexOfTitle.length != 0) {
                    slicesOfTitle.push(mergeIntoSlice(title, 0, title.length, indexOfTitle));
                  }

                  var slicesOfContent = [];
                  while (indexOfContent.length != 0) {
                    var item = indexOfContent[indexOfContent.length - 1];
                    var position = item.position;
                    var word = item.word;
                    // cut out 100 characters
                    var start = position - 20;
                    var end = position + 80;
                    if(start < 0){
                      start = 0;
                    }
                    if (end < position + word.length) {
                      end = position + word.length;
                    }
                    if(end > content.length){
                      end = content.length;
                    }
                    slicesOfContent.push(mergeIntoSlice(content, start, end, indexOfContent));
                  }

                  // sort slices in content by search text's count and hits' count

                  slicesOfContent.sort(function (sliceLeft, sliceRight) {
                    if (sliceLeft.searchTextCount !== sliceRight.searchTextCount) {
                      return sliceRight.searchTextCount - sliceLeft.searchTextCount;
                    } else if (sliceLeft.hits.length !== sliceRight.hits.length) {
                      return sliceRight.hits.length - sliceLeft.hits.length;
                    } else {
                      return sliceLeft.start - sliceRight.start;
                    }
                  });

                  // select top N slices in content

                  var upperBound = parseInt('1');
                  if (upperBound >= 0) {
                    slicesOfContent = slicesOfContent.slice(0, upperBound);
                  }

                  // highlight title and content

                  function highlightKeyword(text, slice) {
                    var result = '';
                    var prevEnd = slice.start;
                    slice.hits.forEach(function (hit) {
                      result += text.substring(prevEnd, hit.position);
                      var end = hit.position + hit.length;
                      result += '<b class="search-keyword">' + text.substring(hit.position, end) + '</b>';
                      prevEnd = end;
                    });
                    result += text.substring(prevEnd, slice.end);
                    return result;
                  }

                  var resultItem = '';

                  if (slicesOfTitle.length != 0) {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + highlightKeyword(title, slicesOfTitle[0]) + "</a>";
                  } else {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + title + "</a>";
                  }

                  slicesOfContent.forEach(function (slice) {
                    resultItem += "<a href='" + articleUrl + "'>" +
                      "<p class=\"search-result\">" + highlightKeyword(content, slice) +
                      "...</p>" + "</a>";
                  });

                  resultItem += "</li>";
                  resultItems.push({
                    item: resultItem,
                    searchTextCount: searchTextCount,
                    hitCount: hitCount,
                    id: resultItems.length
                  });
                }
              })
            };
            if (keywords.length === 1 && keywords[0] === "") {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-search fa-5x" /></div>'
            } else if (resultItems.length === 0) {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-frown-o fa-5x" /></div>'
            } else {
              resultItems.sort(function (resultLeft, resultRight) {
                if (resultLeft.searchTextCount !== resultRight.searchTextCount) {
                  return resultRight.searchTextCount - resultLeft.searchTextCount;
                } else if (resultLeft.hitCount !== resultRight.hitCount) {
                  return resultRight.hitCount - resultLeft.hitCount;
                } else {
                  return resultRight.id - resultLeft.id;
                }
              });
              var searchResultList = '<ul class=\"search-result-list\">';
              resultItems.forEach(function (result) {
                searchResultList += result.item;
              })
              searchResultList += "</ul>";
              resultContent.innerHTML = searchResultList;
            }
          }

          if ('auto' === 'auto') {
            input.addEventListener('input', inputEventFunction);
          } else {
            $('.search-icon').click(inputEventFunction);
            input.addEventListener('keypress', function (event) {
              if (event.keyCode === 13) {
                inputEventFunction();
              }
            });
          }

          // remove loading animation
          $(".local-search-pop-overlay").remove();
          $('body').css('overflow', '');

          proceedsearch();
        }
      });
    }

    // handle and trigger popup window;
    $('.popup-trigger').click(function(e) {
      e.stopPropagation();
      if (isfetched === false) {
        searchFunc(path, 'local-search-input', 'local-search-result');
      } else {
        proceedsearch();
      };
    });

    $('.popup-btn-close').click(onPopupClose);
    $('.popup').click(function(e){
      e.stopPropagation();
    });
    $(document).on('keyup', function (event) {
      var shouldDismissSearchPopup = event.which === 27 &&
        $('.search-popup').is(':visible');
      if (shouldDismissSearchPopup) {
        onPopupClose();
      }
    });
  </script>





  

  
  <script src="https://cdn1.lncld.net/static/js/av-core-mini-0.6.4.js"></script>
  <script>AV.initialize("C4C53NNHHx80rdEcr9XGvVER-gzGzoHsz", "onx6D9nlRn56BhlHoI3E08PQ");</script>
  <script>
    function showTime(Counter) {
      var query = new AV.Query(Counter);
      var entries = [];
      var $visitors = $(".leancloud_visitors");

      $visitors.each(function () {
        entries.push( $(this).attr("id").trim() );
      });

      query.containedIn('url', entries);
      query.find()
        .done(function (results) {
          var COUNT_CONTAINER_REF = '.leancloud-visitors-count';

          if (results.length === 0) {
            $visitors.find(COUNT_CONTAINER_REF).text(0);
            return;
          }

          for (var i = 0; i < results.length; i++) {
            var item = results[i];
            var url = item.get('url');
            var time = item.get('time');
            var element = document.getElementById(url);

            $(element).find(COUNT_CONTAINER_REF).text(time);
          }
          for(var i = 0; i < entries.length; i++) {
            var url = entries[i];
            var element = document.getElementById(url);
            var countSpan = $(element).find(COUNT_CONTAINER_REF);
            if( countSpan.text() == '') {
              countSpan.text(0);
            }
          }
        })
        .fail(function (object, error) {
          console.log("Error: " + error.code + " " + error.message);
        });
    }

    function addCount(Counter) {
      var $visitors = $(".leancloud_visitors");
      var url = $visitors.attr('id').trim();
      var title = $visitors.attr('data-flag-title').trim();
      var query = new AV.Query(Counter);

      query.equalTo("url", url);
      query.find({
        success: function(results) {
          if (results.length > 0) {
            var counter = results[0];
            counter.fetchWhenSave(true);
            counter.increment("time");
            counter.save(null, {
              success: function(counter) {
                var $element = $(document.getElementById(url));
                $element.find('.leancloud-visitors-count').text(counter.get('time'));
              },
              error: function(counter, error) {
                console.log('Failed to save Visitor num, with error message: ' + error.message);
              }
            });
          } else {
            var newcounter = new Counter();
            /* Set ACL */
            var acl = new AV.ACL();
            acl.setPublicReadAccess(true);
            acl.setPublicWriteAccess(true);
            newcounter.setACL(acl);
            /* End Set ACL */
            newcounter.set("title", title);
            newcounter.set("url", url);
            newcounter.set("time", 1);
            newcounter.save(null, {
              success: function(newcounter) {
                var $element = $(document.getElementById(url));
                $element.find('.leancloud-visitors-count').text(newcounter.get('time'));
              },
              error: function(newcounter, error) {
                console.log('Failed to create');
              }
            });
          }
        },
        error: function(error) {
          console.log('Error:' + error.code + " " + error.message);
        }
      });
    }

    $(function() {
      var Counter = AV.Object.extend("Counter");
      if ($('.leancloud_visitors').length == 1) {
        addCount(Counter);
      } else if ($('.post-title-link').length > 1) {
        showTime(Counter);
      }
    });
  </script>



  

  

  
  

  

  

  
  <script type="text/javascript" src="/blog/js/src/exturl.js?v=5.1.4"></script>


  <!-- 页面点击小红心 -->
<script type="text/javascript" src="/js/src/love.js"></script>

</body>
</html>
